Browsing by Author "Curi, Nilton"
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Item Foliar elemental analysis of Brazilian crops via portable x-ray fluorescence spectrometry(2020) Borges, Camila S.; Weindorf, David C. (TTU); Carvalho, Geila S.; Guilherme, Luiz R.G.; Takayama, Thalita; Curi, Nilton; Lima, Geraldo J.E.O.; Ribeiro, Bruno T. (TTU)Foliar analysis is very important for the nutritional management of crops and as a supplemental parameter for soil fertilizer recommendation. The elemental composition of plants is traditionally obtained by laboratory-based methods after acid digestion of ground and sieved leaf samples. This analysis is time-consuming and generates toxic waste. By comparison, portable X-ray fluorescence (pXRF) spectrometry is a promising technology for rapid characterization of plants, eliminating such constraints. This worked aimed to assess the pXRF performance for elemental quantification of leaf samples from important Brazilian crops. For that, 614 samples from 28 plant species were collected across different regions of Brazil. Ground and sieved samples were analyzed after acid digestion (AD), followed by quantification via inductively coupled plasma optical emission spectroscopy (ICP-OES) to determine the concentration of macronutrients (P, K, Ca, Mg, and S) and micronutrients (Fe, Zn, Mn, and Cu). The same plant nutrients were directly analyzed on ground leaf samples via pXRF. Four certified reference materials (CRMs) for plants were used for quality assurance control. Except for Mg, a very strong correlation was observed between pXRF and AD for all plant-nutrients and crops. The relationship between methods was nutrient-and crop-dependent. In particular, eucalyptus displayed optimal correlations for all elements, except for Mg. Opposite to eucalyptus, sugarcane showed the worst correlations for all the evaluated elements, except for S, which had a very strong correlation coefficient. Results demonstrate that for many crops, pXRF can reasonably quantify the concentration of macro-and micronutrients on ground and sieved leaf samples. Undoubtedly, this will contribute to enhance crop management strategies concomitant with increasing food quality and food security.Item Portable x-ray fluorescence (pXRF) spectrometry applied to the prediction of chemical attributes in inceptisols under different land use Espectrometria portátil de fluorescência de raios-x (pXRF) aplicada à predição de atributos químicos de cambissolos sob diferentes usos(2018) Teixeira, Anita Fernanda dos Santos; Weindorf, David C. (TTU); Silva, Sérgio Henrique Godinho; Guilherme, Luiz Roberto Guimarães; Curi, NiltonPortable X-ray fluorescence (pXRF) spectrometry has been increasingly adopted for varying studies worldwide. This work aimed at characterizing effects of soil management on the content of chemical elements detected by pXRF in managed and unmanaged areas of Inceptisols, and evaluating the potential of using pXRF data to generate prediction models for soil fertility attributes, evaluating the effect of land uses on such models. Samples were collected in A, B, and C horizons of soils under native forest, native Cerrado, coffee crops with 1 and 5 years of implantation and eucalyptus. Soil fertility attributes were determined through laboratory analyses, whereas, elemental contents were obtained through pXRF analysis. PXRF data were used for modeling (regressions) and validation of soil fertility attributes and necessity of lime (NL) application, with or without distinction between managed and unmanaged areas. Management practices on coffee crops increased the levels of Sr, CaO, P 2 O 5 , Cu, and Zn. CaO content was efficient for prediction of exchangeable Ca 2+ contents (R 2 = 0.91), pH (R 2 = 0.88), base saturation (R 2 = 0.89) in managed areas. General models presented adequate results to predict exchangeable Ca 2+ (R 2 = 0.92), pH (R 2 = 0.85), and base saturation (R 2 = 0.90). Models for unmanaged areas were less effective. PXRF detected modifications in elemental contents caused by management practices and provided reliable predictions of soil fertility attributes.